For TDU2, i'd have one for 'F'
Fictional Location
I was playing GTA: San Andreas the other day, and noticed that although being smaller than TDU in landmass, It feels less tedious going all the way around the map. There's loads of different kinds of terrain, and although being fictional, it can feel more realistic than TDU for enviroment, what with the better use of elevation in city areas, less repetitive scenery, different kinds of road (main roads, highways, dirt tracks, runways, Back alleys) Land features (railways and rivers) and in general, the whole map is more accessible (most mountains can be driven up in anything as underpowered as a golf kart) wheras in TDU huge sections of the map are just terrain to look at. Also, GTA:SA has a pretty good police system, better than TDU's. Oh, and basic weather. All on a PS2
Now this is a whole generation later, so it could theoretically be the same size but so realistic looking your eyes would explode, and remember, GTA:SA could do this on old hardware, and model pedestrians, and sort the story, and accomodate for planes, and boats, and trains, and then theres the whole off the road section with guns, health, relationships.
Imagine GTA:SA but only worrying about the roads. No developer focus on Character, Weapons, Planes/Boats etc., Story, OTT police system involving Tanks, Building interiors.
Now add the extra power that the current gen of consoles provides.
Alternatively, look at GTA IV, a packed metropolitan enviroment, almost the size of SanAndreas's map. Now, TDU wouldnt need this style enviroment, frankly, GTA IV sucks as a race enviroment. Who needs such a vertical enviroment when you are stuck at road level? Also hell of a lot of building interiors are rendered (they can go too). But look at the map, It's huge.
The traffic in GTA IV is exactly what TDU needs, as is the weather. the police system seems about right for TDU aswell, possibly toned down though, no police with guns to keep it as 'E'. GTA IV can do all of these simultaneously, and more. Even with 16 people doing it at the same time. Surely TDU2 could do this with ease?